Generally, this inventive technology relates to substance analysis and/or processing. More specifically, the inventive technology, in at least one embodiment, relates to in-vessel generation of a material from a solution of interest as part of a processing and/or analysis operation. Preferred embodiments of the in-vessel material generation (e.g., in-vessel solid material generation) include precipitation; in certain embodiments, analysis and/or processing of the solution of interest may include dissolution of the material, perhaps as part of a successive dissolution protocol using solvents of increasing ability to dissolve the material, in order to gain a desired amount of information about the solution of interest or to process a solution of interest as desired. Applications include, but are by no means limited to estimation of a coking onset and solution (e.g., oil) fractionating.